'Smallville' Star Sam Jones III Says Allison Mack Was Normal On Set

One of Allison Mack's co-stars on "Smallville" says she was fairly normal while shooting the show, and never showed any signs she might have been part of an alleged sex cult.

We got Sam Jones III -- who starred alongside Mack for 3 seasons -- and he tells us she had a boyfriend at the time, and he never suspected she would get arrested for alleged ties to the self-help group, Nxivm -- for which she's accused of recruiting women to be "sex slaves."

Smallville's Pete Ross offered his ex-castmate some advice ahead of her trial, where she's facing sex trafficking and conspiracy charges ... and could get 15 years in prison. His tip has to do with the residuals from the show, which -- as Sam showed us -- are still pretty fat.